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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.math.genetics;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    /**<a name="line.19"></a>
<FONT color="green">020</FONT>     * Individual in a population. Chromosomes are compared based on their fitness.<a name="line.20"></a>
<FONT color="green">021</FONT>     *<a name="line.21"></a>
<FONT color="green">022</FONT>     * The chromosomes are IMMUTABLE, and so their fitness is also immutable and<a name="line.22"></a>
<FONT color="green">023</FONT>     * therefore it can be cached.<a name="line.23"></a>
<FONT color="green">024</FONT>     *<a name="line.24"></a>
<FONT color="green">025</FONT>     * @since 2.0<a name="line.25"></a>
<FONT color="green">026</FONT>     * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $<a name="line.26"></a>
<FONT color="green">027</FONT>     */<a name="line.27"></a>
<FONT color="green">028</FONT>    public abstract class Chromosome implements Comparable&lt;Chromosome&gt;,Fitness {<a name="line.28"></a>
<FONT color="green">029</FONT>    <a name="line.29"></a>
<FONT color="green">030</FONT>        /**<a name="line.30"></a>
<FONT color="green">031</FONT>         * Cached value of the fitness of this chromosome.<a name="line.31"></a>
<FONT color="green">032</FONT>         */<a name="line.32"></a>
<FONT color="green">033</FONT>        private double fitness = Double.MIN_VALUE;<a name="line.33"></a>
<FONT color="green">034</FONT>    <a name="line.34"></a>
<FONT color="green">035</FONT>        /**<a name="line.35"></a>
<FONT color="green">036</FONT>         * Access the fitness of this chromosome. The bigger the fitness, the better<a name="line.36"></a>
<FONT color="green">037</FONT>         * the chromosome.<a name="line.37"></a>
<FONT color="green">038</FONT>         *<a name="line.38"></a>
<FONT color="green">039</FONT>         * Computation of fitness is usually very time-consuming task, therefore the<a name="line.39"></a>
<FONT color="green">040</FONT>         * fitness is cached.<a name="line.40"></a>
<FONT color="green">041</FONT>         *<a name="line.41"></a>
<FONT color="green">042</FONT>         * @return the fitness.<a name="line.42"></a>
<FONT color="green">043</FONT>         */<a name="line.43"></a>
<FONT color="green">044</FONT>        public double getFitness() {<a name="line.44"></a>
<FONT color="green">045</FONT>            if (this.fitness == Double.MIN_VALUE) {<a name="line.45"></a>
<FONT color="green">046</FONT>                // no cache - compute the fitness<a name="line.46"></a>
<FONT color="green">047</FONT>                this.fitness = fitness();<a name="line.47"></a>
<FONT color="green">048</FONT>            }<a name="line.48"></a>
<FONT color="green">049</FONT>            return this.fitness;<a name="line.49"></a>
<FONT color="green">050</FONT>        }<a name="line.50"></a>
<FONT color="green">051</FONT>    <a name="line.51"></a>
<FONT color="green">052</FONT>        /**<a name="line.52"></a>
<FONT color="green">053</FONT>         * Compares two chromosomes based on their fitness. The bigger the fitness,<a name="line.53"></a>
<FONT color="green">054</FONT>         * the better the chromosome.<a name="line.54"></a>
<FONT color="green">055</FONT>         *<a name="line.55"></a>
<FONT color="green">056</FONT>         * @param another another chromosome to compare<a name="line.56"></a>
<FONT color="green">057</FONT>         * @return<a name="line.57"></a>
<FONT color="green">058</FONT>         * &lt;ul&gt;<a name="line.58"></a>
<FONT color="green">059</FONT>         *     &lt;li&gt;-1 if &lt;code&gt;another&lt;/code&gt; is better than &lt;code&gt;this&lt;/code&gt;&lt;/li&gt;<a name="line.59"></a>
<FONT color="green">060</FONT>         *     &lt;li&gt;1 if &lt;code&gt;another&lt;/code&gt; is worse than &lt;code&gt;this&lt;/code&gt;&lt;/li&gt;<a name="line.60"></a>
<FONT color="green">061</FONT>         *     &lt;li&gt;0 if the two chromosomes have the same fitness&lt;/li&gt;<a name="line.61"></a>
<FONT color="green">062</FONT>         * &lt;/ul&gt;<a name="line.62"></a>
<FONT color="green">063</FONT>         */<a name="line.63"></a>
<FONT color="green">064</FONT>        public int compareTo(Chromosome another) {<a name="line.64"></a>
<FONT color="green">065</FONT>            return ((Double)this.getFitness()).compareTo(another.getFitness());<a name="line.65"></a>
<FONT color="green">066</FONT>        }<a name="line.66"></a>
<FONT color="green">067</FONT>    <a name="line.67"></a>
<FONT color="green">068</FONT>        /**<a name="line.68"></a>
<FONT color="green">069</FONT>         * Returns &lt;code&gt;true&lt;code&gt; iff &lt;code&gt;another&lt;/code&gt; has the same<a name="line.69"></a>
<FONT color="green">070</FONT>         * representation and therefore the same fitness. By default, it returns<a name="line.70"></a>
<FONT color="green">071</FONT>         * false -- override it in your implementation if you need it.<a name="line.71"></a>
<FONT color="green">072</FONT>         * @param another chromosome to compare<a name="line.72"></a>
<FONT color="green">073</FONT>         * @return true if &lt;code&gt;another&lt;/code&gt; is equivalent to this chromosome<a name="line.73"></a>
<FONT color="green">074</FONT>         */<a name="line.74"></a>
<FONT color="green">075</FONT>        protected boolean isSame(Chromosome another) {<a name="line.75"></a>
<FONT color="green">076</FONT>            return false;<a name="line.76"></a>
<FONT color="green">077</FONT>        }<a name="line.77"></a>
<FONT color="green">078</FONT>    <a name="line.78"></a>
<FONT color="green">079</FONT>        /**<a name="line.79"></a>
<FONT color="green">080</FONT>         * Searches the &lt;code&gt;population&lt;/code&gt; for another chromosome with the same<a name="line.80"></a>
<FONT color="green">081</FONT>         * representation. If such chromosome is found, it is returned, if no such<a name="line.81"></a>
<FONT color="green">082</FONT>         * chromosome exists, returns &lt;code&gt;null&lt;/code&gt;.<a name="line.82"></a>
<FONT color="green">083</FONT>         *<a name="line.83"></a>
<FONT color="green">084</FONT>         * @param population<a name="line.84"></a>
<FONT color="green">085</FONT>         *            Population to search<a name="line.85"></a>
<FONT color="green">086</FONT>         * @return Chromosome with the same representation, or &lt;code&gt;null&lt;/code&gt; if<a name="line.86"></a>
<FONT color="green">087</FONT>         *         no such chromosome exists.<a name="line.87"></a>
<FONT color="green">088</FONT>         */<a name="line.88"></a>
<FONT color="green">089</FONT>        protected Chromosome findSameChromosome(Population population) {<a name="line.89"></a>
<FONT color="green">090</FONT>            for (Chromosome anotherChr : population) {<a name="line.90"></a>
<FONT color="green">091</FONT>                if (this.isSame(anotherChr))<a name="line.91"></a>
<FONT color="green">092</FONT>                    return anotherChr;<a name="line.92"></a>
<FONT color="green">093</FONT>            }<a name="line.93"></a>
<FONT color="green">094</FONT>            return null;<a name="line.94"></a>
<FONT color="green">095</FONT>        }<a name="line.95"></a>
<FONT color="green">096</FONT>    <a name="line.96"></a>
<FONT color="green">097</FONT>        /**<a name="line.97"></a>
<FONT color="green">098</FONT>         * Searches the population for a chromosome representing the same solution,<a name="line.98"></a>
<FONT color="green">099</FONT>         * and if it finds one, updates the fitness to its value.<a name="line.99"></a>
<FONT color="green">100</FONT>         *<a name="line.100"></a>
<FONT color="green">101</FONT>         * @param population<a name="line.101"></a>
<FONT color="green">102</FONT>         *            Population to search<a name="line.102"></a>
<FONT color="green">103</FONT>         */<a name="line.103"></a>
<FONT color="green">104</FONT>        public void searchForFitnessUpdate(Population population) {<a name="line.104"></a>
<FONT color="green">105</FONT>            Chromosome sameChromosome = findSameChromosome(population);<a name="line.105"></a>
<FONT color="green">106</FONT>            if (sameChromosome != null) {<a name="line.106"></a>
<FONT color="green">107</FONT>                fitness = sameChromosome.getFitness();<a name="line.107"></a>
<FONT color="green">108</FONT>            }<a name="line.108"></a>
<FONT color="green">109</FONT>        }<a name="line.109"></a>
<FONT color="green">110</FONT>    <a name="line.110"></a>
<FONT color="green">111</FONT>    }<a name="line.111"></a>




























































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